The potential expansion across China underlines the ambition of Tesco to grow its online business around the world.

The company is the largest online food retailer in the world and already has an internet business in most of the 14 countries where it has stores.

In the next few months it will launch online businesses in Bangkok, Turkey, and Shanghai, where Tesco also has stores. Tesco will officially launch its online food business in Bangkok, Thailand, next month and start taking online food orders in Shanghai in June or July.

The company believes that launching in a major city is the most prudent way to begin an online business, but it has aspirations to expand across Thailand and China

Frans Falize, the international director for tesco.com, said the retailer has the capacity to launch in 50 cities across China. However, this is dependant on the Shanghai business being deemed a success and Mr Falize said China is an "extremely complicated market". He added: "We are taking it step-by-step. We are doing alot of work in China."

Tesco's international online business uses the same operational model and technological infrastructure as the UK business, which first launched on the internet in 1997.

However, the retailer is also tweaking its system to meet the demands of each market. For example, in Bangkok, Tesco has had to reduce the size of its vans to meet local regulations and introduce new cooling equipment to protect fresh food from the searing Thai temperatures. In addition, the company will extend its one-hour delivery slots in Bangkok because of the heavy traffic. Mr Falize said: "A one-hour slot in Bangkok between 4 and 8pm would be suicidal."

The lack of debit and credit cards in China and Thailand mean that Tesco is also considering alternative forms of payment, including allowing customers in those countries to pay by cash on delivery, although this is yet to be approved by management because of the costs and the increased risk of theft posed by the delivery vans carrying large amounts of cash.

The scale and importance of Tesco's online aspirations was highlighted by comments by chief executive Philip Clarke at a conference last week.

Mr Clarke said Tesco intends to increase its investment in digital technology to $750m (£492m) this year and added: "In the future, app development is going to be just as important as property development."